As one kind of the latest developed input and display devices, touch screens are the most simple, convenient, and natural manner of human-computer interaction, and have been widely used as display screens for mobile phones, tablet PCs or computers. However, for some large-size screens, for example, TV sets of 110 inch, if touch interaction is employed, some portions of the screens may be impossible or hard to be touched by finger due to the large size. For example, when the large screens are hanged at high positions, they are inconvenient to be touched.